In the case of a polymer-dispersed liquid crystal device, indium tin oxide, which is used as an electrode material, is expensive due to the use of a rare metal, and requires a vacuum deposition process to form an electrode, undesirably causing complicated processing and making it impossible to manufacture a large-area device. Furthermore, it is weakly resistant to impacts, and is thus limited in usefulness in manufacturing flexible devices.
Recently, attempts are being made to form a transparent electrode layer using a flexible conductive polymer such as poly(ethylenedioxythiophene) as the electrode material of a polymer-dispersed liquid crystal device.
However, in the fabrication of a polymer-dispersed liquid crystal device, when a poly(ethylenedioxythiophene) layer having strong acidity and a polymer-dispersed liquid crystal layer come into direct contact with each other, they are dissolved in each other and may degrade, undesirably losing respective functions as the electrode and the driving part. Thus, with the goal of solving problems with the conventional polymer-dispersed liquid crystal device using the conductive polymer transparent electrode, for example, Korean Patent Application No. 2008-0065637, entitled “Electrically conductive polymer coating composition for manufacturing electrode of polymer-dispersed liquid crystal smart window”, discloses an electrically conductive coating composition for improving the durability of an electrically conductive coating film by forming a cured coating without deteriorating electrical conductivity by adding poly(ethylenedioxythiophene) with trialkoxysilanealkyl(meth)acrylate as an electrode coating material of a polymer-dispersed liquid crystal smart window.
Although the durability of the conductive coating film itself may be improved, the degree of improvement thereof is not satisfactory and the manufacturing cost is increased due to the essential use of a photoinitiator.